Construction Calculator - Construction Converters

Square Footage Calculator

Calculate square feet, square yards, waste area, and material cost.

Reviewed: August 26, 2026

Calculate Square Footage

For the Square Footage Calculator, enter length, width, waste allowance, material price, and coverage per unit. It separates measured area from allowance-adjusted order area, then reports square yards, package count, and optional material cost.

Construction measuring tools arranged beside a residential building project

Formula used

Area = length × width; order area = area × (1 + waste ÷ 100); square yards = order area ÷ 9

Square Footage Calculator measurement plan showing Length feet, Width feet, Waste allowance percent

Worked square footage example

Square Footage Calculator example: 25.9 ft × 15.2 ft = 393.68 ft². With 10% allowance the order area is 433.05 ft², equal to 48.12 yd².

What the converted result represents

Use raw square feet for area reporting; apply waste and package coverage only when converting that area into a specific product order.

Limits of the geometric model

Wall offsets, columns, curves, measurement rounding, and whether openings should be included depend on the material takeoff that follows.

Questions specific to this calculation

Does square footage require a waste allowance?

Enter compatible length and width measurements for one rectangle. Break L-shaped or irregular spaces into rectangles and add their areas.